Error detection
View Patent ↗A method of error detection for a data packet, the method comprising the steps of: i) identifying a set of non-compliances (N), the non-compliances being illegal bit sequences according to a coding standard; ii) identifying a first subset (N+) of non-compliances that are to be treated as errors; iii) identifying a second subset (N.) of non-acceptable near-compliances; iv) decoding the data packet according to the coding standard; and v) adaptively deciding based on the first and second subsets whether to treat a detected non-compliance within the decoded data packet as an error or as an acceptable near-compliance.
1. A method of error detection for a data packet, the method comprising the steps of:
i) identifying a set of non-compliances, the non-compliances being illegal bit sequences according to a coding standard;
ii) identifying as first subset of non-compliances that are to be treated as errors;
iii) identifying a second subset of non-compliances that are to be treated as acceptable near-compliances;
iv) decoding the data packet according to the coding standard; and
v) adaptively deciding based on the first and second subsets whether to treat a detected non-compliance within the decoded data packet as an error or as an acceptable near compliance.
2. The method of claim 1 wherein the set of non-compliances defines the set of all possible non-compliances according to the coding standard.
3. The method of claim 1 wherein the first subset of non-compliances consists of all non-compliances that cannot be a result of a data packet being non-compliant with the coding standard.
4. The method of claim 1 wherein the first and second subsets are identified by static statistical analysis of non-compliances in a series of data packets encoded according to the coding standard.
5. The method of claim 1 wherein the set of non-compliances consists of the first and second subsets and a third subset, the first, second and third subsets being mutually exclusive.
6. The method of claim 4 wherein identifying the second subset comprises identifying non-compliances in the series of data packets according to their proximity with neighbouring non-compliances.
7. The method of claim 1 wherein the step of adaptively deciding occurs during the step of decoding the data packet.
8. The method of claim 7 wherein decoding the data packet ceases when a detected non-compliance is treated as an error.
9. The method of claim 7 wherein decoding the data packet continues when a detected non-compliance is treated as an acceptable near-compliance.
10. The method of claim 1 wherein steps iv) and v) are applied to a plurality of encoded data packets.
11. The method of claim 10 wherein the step of adaptively deciding comprises determining a balance based on a local distribution of non-compliances, the balance indicating whether non-compliances that are not members of the first or second subsets are to be treated as being errors or as acceptable non-compliances.
12. The method of claim 11 wherein the balance is updated after decoding of each data packet.
13. The method ref claim 11 wherein the balance is dependent upon the presence of non-compliances in a current data packet and on non-compliances present in a history of a plurality of previously decoded data packets.
14. The method of claim 11 wherein to separate balance is determined for each type of non-compliance that is not a member of the first or second subsets, each balance indicating whether the corresponding non-compliance is be treated as an error or an acceptable near-compliance.
15. The method of claim 1 wherein the data packet contains audio and/or video information.
16. The method of claim 10 wherein the plurality of encoded data packets are in the form of a bit stream.
17. An apparatus for decoding a data packet, the apparatus comprising:
a decoder configured to decode the data packet;
an error detection module configured to detect non-compliances within the data packet, the non-compliances being illegal bit sequences according to a coding standard;
a reconstruction module configured to reconstruct information from symbols decoded by the decoder according to the coding standard;
an adaptive decision module configured to determine whether a non-compliance detected by the error detection module is likely to be an error occurrence or an acceptable near-compliance occurrence,
wherein the apparatus is configured to
i) identify a set of non-compliances according to the coding standard;
ii) identify a first subset of non-compliances that are to be treated as errors;
iii) identify a second subset of non-compliances that are to be treated as acceptable near-compliances;
iv) decode the data packet; and
v) adaptively decide based on the first and second subsets whether to treat detected non-compliance within the decoded data packet as an error or as an acceptable near-compliance.
18. The apparatus of claim 17 wherein the set of non-compliances defines the set of all possible non-compliances according to the coding standard.
19. The apparatus of claim 17 wherein the first subset of non-compliances consists of all non-compliances that cannot be a result of a data packet being non-compliant with the coding standard.
20. The apparatus of claim 17 wherein the apparatus is configured to identify the first and second subsets by static statistical analysis of non-compliances in a series of data packets encoded according to the coding standard.
21. The apparatus of claim 17 wherein the set of non-compliances consists of the first and second subsets and a third subset, the first, second and third subsets being mutually exclusive.
22. The apparatus of claim 20 wherein identifying the second subset comprises identifying non-compliances in the series of data packets according to their proximity with neighbouring non-compliances.
23. The apparatus of claim 17 wherein the apparatus is configured to adaptively decide during decoding of the data packet.
24. The apparatus of claim 23 wherein the apparatus is configured to cease decoding the data packet when a detected non-compliance is treated as an error.
25. The apparatus of claim 23 wherein the apparatus is configured to continue decoding the data packet when a detected non-compliance is treated as an acceptable near-compliance.
26. The apparatus of claim 17 wherein the apparatus is configured to decode a plurality of encoded data packets.
27. The apparatus of claim 26 wherein the apparatus is configured to determine a balance based on a local distribution of non-compliances, the balance indicating whether non-compliances that are not members of the first or second subsets are to be treated as being errors or as acceptable non-compliances.
28. The apparatus of claim 27 wherein the apparatus is configured to update the balance after decoding of each data packet.
29. The apparatus of claim 27 wherein the balance is dependent upon the presence of non-compliances in a current data packet and on non compliances present in a history of a plurality of previously decoded data packets.
30. The apparatus of claim 27 wherein a separate balance is determined for each type of non-compliance that is not a member of the first or second subsets, each balance indicating whether the corresponding non-compliance is to be treated as an error or an acceptable near-compliance.
31. The apparatus of claim 17 wherein the data packet contains audio and/or video information.
32. The apparatus of claim 26 wherein the plurality of encoded data packets are in the form of a bit stream.